That's the approach I thought I was taking with my VI, however, I could be doing it wrong. This is the first time I've really used properties and methods.
The first plot I add contains the 4 specific points of value, in which I try to change point size and color, and then plot the original data. As the program is running, I think I see 4 points that are connected (don't want them connected), but they don't appear to be any different color or size. So while it doesn't give me an error, I also don't see a change.